Field
The present specification generally relates to infrared detector devices and, more particularly, to tunneling barrier infrared detector devices and structures for reducing dark current, lowering bias voltage, and increasing operating temperature for infrared detectors such as focal plane arrays.
Technical Background
The nBn device structure has been used to improve the operating temperature of photoconductive infrared detectors by blocking the flow of electrons. The nBn device structure generally includes an n-type absorber layer, a barrier layer to block majority carriers, and an n-type contact layer. Such nBn devices can be used to improve the operating temperature of an infrared focal plane arrays (FPA). FPA devices using the nBn device structure require significant bias to turn on the photocurrent, while the dark current density increases at the same time. To increase the operating temperature further, it is necessary to further reduce the dark current and lower the bias voltage required to turn on the photocurrent. If a zero bias photoresponse can be achieved, it will provide more room for FPA biasing optimizations and thus better imaging quality.
Accordingly, a need exists for alternative infrared detector devices with lower dark current, lower required bias voltages, and increased operating temperature.